In the process of manufacturing the metal oxide semiconductor array substrate, the metal oxide semiconductor may produce thermo-electronic effect with the decrease of the channel length, which results in a relatively large drain current, degrades the electrical performance of the metal oxide semiconductor, and influences the manufacturing effect of the metal oxide semiconductor array substrate. Hence, the drain current needs to be restrained.
In the prior art, the drain current is mainly restrained by controlling the length of the lightly doped drain (LDD). The LDD is located at the active layer of the array substrate and is located below the gate, the length of the LDD is determined by the gate line width. Specifically, the length of the LDD can be controlled by prolonging or shortening the time for exposing the LDD, or the gate line width can be controlled by prolonging or shortening the time for etching the gate, so as to control the length of the LDD and achieve the aim of restraining the drain current finally.
However, when controlling the length of the LDD, on the one hand, etching the gate needs to consider the calculation accuracy and stability of the gate line width, meanwhile, when the gate line width is determined, the length of the LDD is also determined, so that the length of the LDD cannot be changed any more; on the other hand, the two processes of exposing the LDD and etching the gate cannot be performed simultaneously, the conditional requirement for controlling the gate line width and the conditional requirement for controlling the length of the LDD are mutually restricted, the conditional requirement of one party has to be sacrificed to meet the conditional requirement of the other party, i.e., the conditional requirement for the gate line width and the conditional requirement for the LDD length cannot be met simultaneously in the manufacturing process, hence, the existing method for manufacturing the array substrate has relatively low control flexibility and relatively poor feasibility to the LDD length.